Secondary structure of charge isomers of myelin basic protein before and after phosphorylation

摘要: Human myelin basic protein (MBP) was fractionated into several of its charge isomers (components). Of these, the secondary structures four before and after phosphorylation have been studied by circular dichroism (CD). None showed any alpha-helical structure. All components varying amounts beta-structure, random structure, turns. Component 1 (C-1), most cationic components, 13%; component 2 (C-2) had 19%; C-3, 17%; C-4, 24% beta-structure. Each phosphorylated with kinase C, from human brain. The extent varied considerably 2.8 +/- 0.6 mol PO4/mol in C-1 to 5.2 0.8 C-4. effect on structure induce beta-structure all components. largest change least surprising result is that although were different extents, amount increased a final proportion 35-40%. Treatment acid phosphatase removed 50% total radioactivity. Although remainder represented approximately protein, unaltered. We concluded single site identified as residues 5-13 critical size for stabilization MBP solution at other sites little influence